Hyponatremia as a predictor of mortality in peritoneal dialysis patients

PLoS One. 2014 Oct 29;9(10):e111373. doi: 10.1371/journal.pone.0111373. eCollection 2014.

Abstract

Background and aim: Hyponatremia is common in patients with chronic kidney disease and is associated with increased mortality in hemodialysis patients. However, few studies have addressed this issue in peritoneal dialysis (PD) patients.

Methods: This prospective observational study included a total of 441 incident patients who started PD between January 2000 and December 2005. Using time-averaged serum sodium (TA-Na) levels, we aimed to investigate whether hyponatremia can predict mortality in these patients.

Results: Among the baseline parameters, serum sodium level was positively associated with serum albumin (β = 0.145; p = 0.003) and residual renal function (RRF) (β = 0.130; p = 0.018) and inversely associated with PD ultrafiltration (β = -0.114; p = 0.024) in a multivariable linear regression analysis. During a median follow-up of 34.8 months, 149 deaths were recorded. All-cause death occurred in 81 (55.9%) patients in the lowest tertile compared to 37 (25.0%) and 31 (20.9%) patients in the middle and highest tertiles, respectively. After adjusting for multiple potentially confounding covariates, increased TA-Na level was associated with a significantly decreased risk of all-cause (HR per 1 mEq/L increase, 0.79; 95% CI, 0.73-0.86; p<0.001) and infection-related (HR per 1 mEq/L increase, 0.77; 95% CI, 0.70-0.85; p<0.001) deaths.

Conclusions: This study showed that hyponatremia is an independent predictor of mortality in PD patients. Nevertheless, whether correcting hyponatremia improves patient survival is unknown. Future interventional studies should address this question more appropriately.

Publication types

  • Clinical Trial
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Hyponatremia / diagnosis*
  • Hyponatremia / etiology
  • Male
  • Middle Aged
  • Peritoneal Dialysis / adverse effects*
  • Peritoneal Dialysis / mortality
  • Renal Insufficiency, Chronic / complications
  • Renal Insufficiency, Chronic / diagnosis
  • Renal Insufficiency, Chronic / therapy

Grant support

This work was supported by the Brain Korea 21 Project for Medical Science, Yonsei University, by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MEST) (No. 2011-0030711), and by a grant of the Korea Healthcare Technology R&D Project, Ministry of Health and Welfare, Republic of Korea (A102065). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.